1. Field of the Invention
The present invention relates to a portable information terminal, and more particularly to a portable information terminal for inputting complicated data in an easy convenient manner.
2. Description of the Related Art
In general, “a portable information terminal” refers to a device which a user can carry with him/her to perform wireless communication with a corresponding communication partner. This portable communication device is classified into various types based on its geometry. For example, a wireless terminal is classified into a bar-type, a flip-type or folder-type in accordance with its geometrical appearance. The bar-type wireless terminal is generally constructed as a single housing having a bar shape. The flip-type or folder type wireless terminal typically has a folder that is pivotably coupled to a single bar-shaped housing by a hinge device to make the folder to be foldable. This configuration of aforementioned bar-type, flip-type or folder-type wireless terminal may easily be understood by those skilled in the art.
Furthermore, the portable wireless terminal may be classified into a neck wearable type or a wrist wearable type based on a use position or the way in which a user puts it on. The neck wearable type wireless terminal is worn around the neck using a string, while the wrist wearable type wireless terminal is worn around the wrist.
Furthermore, the wireless terminal may be classified into a rotation-type or a sliding-type based on an opened and closed way thereof. In the rotation-type wireless terminal, two housings are coupled to each other in a manner in which one housing is capable of being rotatably opened or closed with respect to the other. In the sliding-type wireless terminal, two housings are coupled to each other in a manner in which one housing is capable of being slidably opened or closed with respect to the other through a sliding movement. These foregoing various classified wireless terminals are easily understood by those skilled in the art.
Meanwhile, the aforementioned conventional portable wireless terminals are typically provided with a data input/output unit, respectively. A data input unit typically employs a key pad through which data are input by pressing the key pad. This may also be true for a touch pad or a touch screen. Moreover, a data output unit generally makes use of a Liquid Crystal Display (LCD) for outputting data.
Typically, the key pad used to input data combines a plurality of keys. These keys include numeric keys, character keys, sending keys, end key, functional keys, and the like. In addition, the keys are generally held in place on a top surface of the housing of the portable wireless terminal, and the number of keys is from 15 to 20. The keys are exposed on the top surface the portable wireless terminal so that a user can push them with his/her finger to input desired data.
However, the reality is that users have increasingly higher demands for information and that it is very inconvenient for users to input complicated data using the foregoing number of keys, within the Internet or multimedia environment. The conventional portable wireless terminal has shown a tendency not only to become smaller and lighter but also to reduce dimensions of the housing. This tendency places restrictions on the number of keys that can be set on the terminal. To solve this problem, a voice recognition device or a separate data input unit has been used.
In other cases, the number of keys are increased to allow inputting of complicated data. This increase in the number of keys, however, tends to increase the dimensions of the housing of the conventional portable wireless terminal. Therefore, a problem arises in that the portability of a conventional portable wireless terminal is compromised.